Galls caused by the queen and nymphs of Rhopalo- 

 siphum ribis Linn. 



on 



the leaves of Ribes nigrum Linn. 



PLATE 106. 

 Synonymy of Insect. 



Myzus ribis Kerner. 



Aphis ribis Linn., Schr., Kalt., Walk. 



Rliopalosiphum ribis Koch., Pass. 

 Habitat of the Black Currant.— Cultivated in gardens 



and orchards throughout the whole of Britain. Bentham, 



in "British Flora," p. 164, says: "If anywhere wild, it is 



in the Lake District and Yorkshire." 

 The Gall is formed by the nymphs puncturing the under- 

 side of the leaf and feeding upon the sap. 

 Position. — On the upper surface of the leaf. 

 Manner of Growth. — Convexo-concave blisters all over the 



leaf. 

 Colour. — Yellowish green, orange-yellow, red, brown. 

 Average Dimensions of a Mature Specimen. 



Height, 5 mm. ; length, 10 mm. ; breadth, 7 mm. 

 May be sought during the months of May to October. 

 The Growth is complete by the end of August. 

 The Typical Condition of the gall is multinymphal. 

 ECDYSIS takes place in the gall. The imagines emerge during 



July. 



The leaves of the red currant, Ribes rubruin Linn., are 

 attacked and galled in the same manner. This is caused by an 

 aphis, which, without the aid of a lens, appears to be of the 

 same species as above-mentioned. The markings and coloration, 

 however, are some\\hat different, and the name of Myzus ribis 

 Pass., has been given to it. 



The gall is also figured by Rennie, " Insect Architecture," 

 vol. ii., p. 137 ; Kerner, " Nat. Hist, of Plants," vol. ii., p. 531. 



The illustration is of specimens gathered at Hastings by the 

 author. 



244 



